Causes: Vista defaults to only send the more secure NTLMv2 protocol, which these NAS devices / Samba do not support.
Fixes: Go to Start -> Run -> "secpol.msc". Then goto Local Policies -> Security Options. Find "Network Security: LANManager authentication level". Change the setting from "Send NTLMv2response only" to "Send LM & NTLM - use NTLMv2 session security ifnegotiated". Save the setting and then reboot the computer.
Note: Buffalo has a download that does the same thing,but it involves messing with the registry by incorporating a ".reg"file. It is much better (and probably easier) to just use the abovesteps.
New Note: Seems some copies of Vista do not have"secpol.msc", probably the Home versions(Home Basic and Home Premium).These users will either need to use the download from Buffalo or go into their Registry editor.
Regedit instructions:
- Start->Search Bar or Run and enter "regedit"
- Go to HKEY_LOCAL_MACHINE->SYSTEM->CurrentControlSet->Control->Lsa
- Right-click on "lmcompatibilitylevel" and choose Modify
- Set the Value Data to 2 (default is 3) and click OK
- Exit regedit and reboot
- Try to connect again